CN114148554A - Combined 3D Microgravity Simulation System for Satellite Ground Simulation - Google Patents

Abstract

The application relates to the technical field of microgravity simulation, and discloses a combined three-dimensional microgravity simulation system suitable for satellite ground simulation, which comprises a vertical air floatation microgravity simulation unit, a suspension microgravity simulation unit and a smooth platform; the vertical air floatation microgravity simulation unit comprises a vertical air cylinder, the vertical air cylinder is suspended above the smooth platform through a horizontal air foot, and part of gravity of the simulation aircraft fixed on the top of the vertical air cylinder is balanced by adjusting air pressure in the vertical air cylinder; the hanging microgravity simulation unit comprises a two-dimensional moving platform, a suspension wire, a Z-axis servo motor, a tension sensor, a positioning device and a first controller, wherein the Z-axis servo motor is connected with the simulation aircraft through the suspension wire, the first controller controls the two-dimensional moving platform to move along with the simulation aircraft according to the position of the simulation aircraft measured by the positioning device, and the Z-axis servo motor is controlled to retract or release the suspension wire according to the tension of the suspension wire measured by the tension sensor so as to balance part of gravity of the simulation aircraft.

Description

Combined 3D Microgravity Simulation System for Satellite Ground Simulation

technical field

The present application relates to the technical field of microgravity simulation, in particular to a combined three-dimensional microgravity simulation system suitable for satellite ground simulation.

Background technique

Ground-based microgravity simulation is a new research field that emerged with the development of aerospace technology, and soon became one of the important technologies that the United States, Japan, Canada and other space powers have successively paid attention to. Compared with digital simulation and theoretical evaluation, through microgravity simulation The test data obtained by the simulation is more authentic and reliable, and has irreplaceable advantages. In order to ensure the reliability of the spacecraft's on-orbit operation, the microgravity ground simulation test is an essential work. Although the existing air flotation method can realize gravity compensation or frictionless relative motion conditions to simulate the mechanical environment with little disturbance force in outer space, it lacks the degree of freedom in the vertical direction, and it is difficult to achieve vertical microgravity simulation. , not suitable for the occasion of three-dimensional free movement in the load space. Although the suspension method realizes three-dimensional microgravity simulation, the load it can bear is small, which cannot meet the demand of large load, and the friction force on the rope during movement is large, which seriously affects the test accuracy.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a combined three-dimensional microgravity simulation system suitable for satellite ground simulation, which has the advantages of strong load capacity, long dynamic simulation travel, fast tracking, and high simulation accuracy, and can be adapted to high-speed and high-maneuver simulation of simulated aircraft Flight occasions, including:

Vertical air-floating microgravity simulation unit, suspended microgravity simulation unit and smooth platform;

The vertical air flotation microgravity simulation unit includes a vertical air cylinder, the vertical air cylinder is suspended above the smooth platform through a horizontal air foot and moves in the horizontal direction, and the gas pressure balance in the vertical air cylinder is adjusted by adjusting the air pressure in the vertical air cylinder. A part of the gravity of the simulated aircraft fixed on the top of the vertical cylinder;

The suspended microgravity simulation unit includes a two-dimensional mobile platform, a suspension wire, a Z-axis servo motor, a tension sensor, a positioning device and a first controller. The two-dimensional mobile platform is erected above the smooth platform. The mobile platform can move in the horizontal direction, the Z-axis servo motor arranged on the two-dimensional mobile platform is connected with the simulated aircraft through the suspension wire, and the positioning device is used to measure the position of the simulated aircraft, so the The tension sensor is used to measure the tension of the suspension wire; the first controller is used to control the two-dimensional moving platform to follow the simulated aircraft to move according to the position of the simulated aircraft measured by the positioning device, so as to Keep the suspension wire upright, and control the Z-axis servo motor to retract or release the suspension wire according to the pulling force of the suspension wire measured by the tension sensor, so as to balance a part of the gravity of the simulated aircraft .

Optionally, the first controller is further configured to acquire the jet mass consumed by the simulated aircraft, and control the Z-axis servo motor to adjust the The tension of the suspension.

Optionally, the first controller is also used for:

Obtain the size of the jet port, jet pressure and jet thrust of the simulated aircraft, and determine the disturbance force received by the simulated aircraft;

According to the disturbance force received by the simulated aircraft, the pulling force of the suspension wire is adjusted by the Z-axis servo motor to balance the disturbance force of the aircraft.

Optionally, the vertical air-floating microgravity simulation unit further includes a grating ruler for measuring the height of the vertical air cylinder in the vertical direction.

Optionally, the first controller is also used for:

When it is detected that the vertical cylinder is exhausted to the outside, based on the height of the vertical cylinder in the vertical direction measured by the grating ruler, and the correspondence table between the height of the vertical cylinder and the air flotation force measured in advance, determining the air flotation power currently received by the vertical cylinder;

According to the current air buoyancy disturbance force, the pulling force of the suspension wire is adjusted by the Z-axis servo motor to balance the air buoyancy disturbance force currently received by the vertical cylinder.

Optionally, the vertical cylinder includes a cylinder, an electromagnetic regulating valve, a high-pressure gas cylinder, a ventilation pipe, a pressure sensor and a second controller;

The air outlet of the high-pressure gas cylinder is communicated with the air inlet of the cylinder through the ventilation pipe, and the air outlet and the air inlet of the air cylinder are respectively equipped with electromagnetic regulating valves;

the pressure sensor is used to measure the pressure in the cylinder;

The second controller is used for controlling the opening and closing of the electromagnetic regulating valve to increase or decrease the gas in the cylinder according to the motion state of the simulated aircraft and the pressure measured by the pressure sensor.

Optionally, the electromagnetic regulating valve includes a coarse regulating valve and a fine regulating valve;

The second controller is specifically used to: determine the air intake or air output of the cylinder according to the motion state of the simulated aircraft and the pressure measured by the pressure sensor; if the air intake or the air output is greater than a preset amount If the threshold value is set, the gas volume in the cylinder is adjusted through the coarse adjustment valve, otherwise the gas volume in the cylinder is adjusted through the fine adjustment valve.

Optionally, the second controller is specifically configured to: according to the motion state of the simulated aircraft and the pressure measured by the pressure sensor, use a two-valve segmented Schmises predictive control algorithm to determine the air intake of the cylinder. volume or air output.

Optionally, the second controller is further used to obtain the jet mass consumed by the simulated aircraft, and adjust the gas volume in the cylinder according to the jet mass consumed by the simulated aircraft.

Optionally, the suspended microgravity simulation unit further includes an X-axis linear slide rail, a Y-axis linear slide rail, an X-axis servo motor and a Y-axis servo motor;

The smooth platform is provided with a support frame, X-axis linear slide rails arranged in parallel are installed on both sides of the support frame, and Y-axis linear slide rails are installed in parallel between the X-axis linear slide rails. The Y-axis linear slide rail is driven to move along the X-axis linear slide rail, the two-dimensional moving platform is installed between the Y-axis linear slide rails, and the two-dimensional moving platform is driven by the Y-axis servo motor to move along the Y-axis linear slide rail.

The combined three-dimensional microgravity simulation system suitable for satellite ground simulation provided by the embodiment of the present application balances a part of the gravity of the simulated aircraft through the vertical air-floating microgravity simulation unit, and at the same time balances another part of the simulated aircraft through the suspended microgravity simulation unit. Part of the gravity has realized three-dimensional microgravity simulation, and the combination of suspended air-floating improves the load capacity of the entire system to meet the needs of large loads. In addition, the fast tracking of the simulated aircraft is realized based on the positioning device, combined with the Z-axis servo motor and the tension sensor, to ensure that the suspension wire moves with the simulated aircraft and adjust the tension of the suspension wire in real time, reducing the interference caused by the suspension wire and improving the simulation accuracy. Therefore, the combined three-dimensional microgravity simulation system suitable for satellite ground simulation provided by the embodiment of the present application has the advantages of strong load capacity, long dynamic simulation travel, rapid tracking, and high simulation accuracy, and can be adapted to simulate high-speed and high-maneuverability of aircraft. Simulation flight situation.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a schematic diagram of a combined three-dimensional microgravity simulation system suitable for satellite ground simulation according to an embodiment of the present application.

Detailed ways

The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict; and, based on the embodiments in this application, those of ordinary skill in the art can obtain the results obtained without creative work. All other embodiments fall within the protection scope of the present application.

It is noted that various aspects of embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is illustrative only. Based on this application, one skilled in the art should appreciate that an aspect described herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method may be practiced using any number of the aspects set forth herein. Additionally, such an apparatus may be implemented and/or such a method may be practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.

For the convenience of understanding, the terms involved in the embodiments of the present application are explained below:

Grating ruler: that is, the grating ruler displacement sensor, which is a measurement feedback device that uses the optical principle of the grating. The grating ruler displacement sensor is often used in the closed-loop servo system of the CNC machine tool, and can be used for the detection of linear displacement or angular displacement. The measured output signal is digital pulse, which has the characteristics of large detection range, high detection accuracy and fast response speed.

The Smith predictor control algorithm is a pure lag compensation model proposed by Smith. The core of the algorithm is to add a Smith predictor to the control loop, which is connected in parallel with the conventional controller D(s) to form a pure lag. The compensation controller can make the time lag of the control object fully compensated.

Any number of elements in the drawings is for illustration and not limitation, and any designation is for distinction only and does not have any limiting meaning.

In order to further illustrate the technical solutions provided by the embodiments of the present application, the following detailed descriptions are given in conjunction with the accompanying drawings and specific embodiments.

Referring to FIG. 1, an embodiment of the present application provides a combined three-dimensional microgravity simulation system suitable for satellite ground simulation, including: a vertical air-floating microgravity simulation unit, a suspended microgravity simulation unit, and a horizontal two-dimensional microgravity simulation unit and smooth platform 12. The vertical air-floating microgravity simulation unit includes a vertical cylinder 9 , the horizontal two-dimensional microgravity simulation unit includes a horizontal air foot 11 , and the suspended microgravity simulation unit includes a two-dimensional mobile platform 14 , a suspension wire 7 , and a Z-axis servo motor 3 , a tension sensor 8, a positioning device 6 and a first controller. The first controller is installed on the two-dimensional moving platform 14 and moves together with the two-dimensional moving platform 14 . The smooth platform 12 can be selected as a marble platform.

The vertical cylinder 9 is used to support the simulated aircraft 10 , and the simulated aircraft 10 can be fixed on the top of the vertical cylinder 9 . The vertical cylinder 9 can change the support force provided by the vertical cylinder 9 to the simulated aircraft 10 by adjusting the gas pressure inside, so as to balance a part of the gravity of the simulated aircraft 10 to simulate the weightless state of the aircraft 10 in outer space.

The horizontal two-dimensional microgravity simulation unit adopts the air flotation method, and uses the horizontal air foot and smooth platform to realize the plane two-dimensional microgravity simulation. The horizontal air foot 11 is installed at the bottom of the vertical cylinder 9. After the horizontal air foot 11 is ventilated, it will spray a stable airflow downward, thereby forming an air film between the horizontal air foot 11 and the smooth platform 12, so that the vertical air cylinder 9 is suspended on the smooth platform. 12, in order to reduce the friction during the horizontal movement, and simulate the micro-friction environment in the state of weightlessness in outer space. At the same time, the horizontal air foot 11 can be jetted to the surroundings as required, thereby driving the vertical cylinder 9 to move in the horizontal direction. In the specific implementation, the relevant experimental data, theoretical formulas and experience can be combined to design the structure of the horizontal air foot 11 that meets the requirements for the load mass of the horizontal air foot 11. The design parameters include: the radius of the air foot, the number of orifices on the air foot, and the Orifice diameter, gas film thickness, etc. The horizontal air foot 11 can be equipped with a separate air supply arrangement, or the air supply device of the vertical cylinder 9 can also be used.

The two-dimensional moving platform 14 is erected above the smooth platform 12, and the two-dimensional moving platform 14 can move in the horizontal direction. Taking FIG. 1 as an example, a support frame 13 is provided on the smooth platform 12, two X-axis linear slide rails 4 arranged in parallel are installed on both sides of the support frame 13, and a Y-axis arranged in parallel is installed between the X-axis linear slide rails 4. Linear slide rail 5, two-dimensional moving platform 14 is installed between two Y-axis linear slide rails 5, through Y-axis servo motor 1 can drive two-dimensional moving platform 14 to move along Y-axis linear slide rail 5, through X-axis servo motor 2. The Y-axis linear slide rail 5 can be driven to move along the X-axis linear slide rail 4, thereby realizing the movement of the two-dimensional moving platform 14 in the horizontal direction.

The Z-axis servo motor 3 can be arranged on the two-dimensional moving platform 15 , one end of the suspension wire 7 is connected to the Z-axis servo motor 3 , and the other end of the suspension wire 7 is connected to the simulated aircraft 10 , which can be controlled by the Z-axis servo motor 3 to be retracted or The suspension wire 7 is released, thereby exerting a certain upward pulling force on the simulated aircraft 10 to balance a part of the gravity of the simulated aircraft 10 .

The positioning device 6 is used to measure the position of the simulated aircraft 10, and the positioning device 6 may be an image acquisition device, such as a monocular industrial camera. The positioning device 6 can be installed on the two-dimensional mobile platform 14 and move together with the two-dimensional mobile platform 14, or can be fixed in other places where the position of the simulated aircraft 10 can be observed, which is not limited in this application.

The tension sensor 8 can be installed on the suspension wire 7 for measuring the pulling force of the suspension wire 7 .

The first controller is used to control the two-dimensional mobile platform 14 to move with the simulated aircraft 10 according to the position of the simulated aircraft 10 measured by the positioning device 6 , so as to ensure that the suspension wire 7 is always in a vertical state during the movement of the simulated aircraft 10 to avoid the suspension wire. 7 Apply a horizontal force to the simulator 10. The first controller is also used to control the Z-axis servo motor 3 to retract or release the suspension wire 7 according to the pulling force of the suspension wire 7 measured by the tension sensor 8 to balance a part of the gravity of the simulated aircraft 10 .

During the specific implementation, the load-bearing ratio can be allocated to the vertical air-floating microgravity simulation unit and the suspended microgravity simulation unit in advance. For example, the vertical air-floating microgravity simulation unit bears 70% of the weight of the simulated aircraft, and the suspended microgravity simulation unit bears the simulation 30% of the weight of the aircraft, combined with the actual mass of the simulated aircraft, determine the gravity that the vertical air-floating microgravity simulation unit and the suspended microgravity simulation unit need to balance respectively, and then calculate the internal pressure of the vertical cylinder and the pulling force that the suspension wire needs to provide. . It should be noted that the weight assigned to the suspended microgravity simulation unit cannot exceed the maximum pulling force that the suspension wire can bear, and similarly, the weight allocated to the suspended microgravity simulation unit cannot exceed the maximum load capacity of the vertical cylinder.

The combined three-dimensional microgravity simulation system suitable for satellite ground simulation provided by the embodiment of the present application balances a part of the gravity of the simulated aircraft through the vertical air-floating microgravity simulation unit, and at the same time balances another part of the simulated aircraft through the suspended microgravity simulation unit. Part of the gravity has realized three-dimensional microgravity simulation, and the combination of suspended air-floating improves the load capacity of the entire system to meet the needs of large loads. In addition, the fast tracking of the simulated aircraft is realized based on the positioning device, combined with the Z-axis servo motor and the tension sensor, to ensure that the suspension wire moves with the simulated aircraft and adjust the tension of the suspension wire in real time, reducing the interference caused by the suspension wire and improving the simulation accuracy. Therefore, the combined three-dimensional microgravity simulation system suitable for satellite ground simulation provided by the embodiment of the present application has the advantages of strong load capacity, long dynamic simulation travel, rapid tracking, and high simulation accuracy, and can be adapted to simulate high-speed and high-maneuverability of aircraft. Simulation flight situation.

In a specific implementation, the vertical cylinder includes a cylinder, an electromagnetic regulating valve, a high-pressure gas cylinder, a ventilation pipe, a pressure sensor and a second controller. The air outlet of the high-pressure gas cylinder is communicated with the air inlet of the cylinder through a ventilation pipe, and the high-pressure gas cylinder can be inflated into the cylinder through the ventilation pipe. The air outlet and the air inlet of the cylinder are respectively equipped with electromagnetic regulating valves. In this application, the electromagnetic regulating valve arranged at the air inlet of the cylinder is called the inlet electromagnetic valve, and the electromagnetic regulating valve arranged at the air outlet of the cylinder is called the outlet electromagnetic valve. By controlling the opening and closing of the intake solenoid valve and the exhaust solenoid valve, the cylinder is inflated or exhausted, thereby changing the pressure in the cylinder, thereby adjusting the supporting force for supporting the simulated aircraft. When the intake solenoid valve is opened, the high-pressure gas cylinder is inflated into the air cavity of the cylinder, and the pressure in the air cavity increases, causing the cylinder piston to move upwards, thereby providing greater support for the simulated aircraft; when the exhaust solenoid valve is opened , the external exhaust of the cylinder, the pressure in the air cavity of the cylinder decreases, causing the cylinder piston to move upward, thereby reducing the support force provided by the supporting simulated aircraft.

During specific implementation, a pressure sensor may be arranged in the cylinder to measure the pressure in the cylinder. In order to improve the measurement accuracy of pressure, pressure sensors can be installed at different positions in the cylinder, and the pressure in the air cavity of the cylinder can be more accurately measured according to the measurement fingers of the multiple pressure sensors.

The second controller can control the opening and closing of the electromagnetic regulating valve (including the intake solenoid valve and the exhaust solenoid valve) to increase or decrease the gas in the cylinder according to the motion state of the simulated aircraft and the pressure measured by the pressure sensor. Through the opening and closing of the electromagnetic regulating valve, the constant pressure control of the cylinder can be realized in the dynamic simulation process, and the simulation accuracy can be improved. For example, when the simulated aircraft moves upwards, the intake solenoid valve needs to be opened to make the cylinder piston move upwards to follow the upward movement of the simulated aircraft and provide continuous and stable support for the simulated aircraft; when the simulated aircraft moves downwards, it is necessary to open the air outlet. The solenoid valve makes the cylinder piston move downward to follow the downward movement of the simulated aircraft, providing continuous and stable support for the simulated aircraft; when the pressure in the cylinder is too large, the outlet solenoid valve needs to be opened to exhaust, when the pressure in the cylinder is too high If it is too small, you need to open the intake solenoid valve to charge.

The following is a detailed description of the constant pressure control method of the second controller for the air cavity in the cylinder during the dynamic simulation process.

First, the air cavity pressure in the cylinder can be expressed as:

(1)

(1)

为气腔压强的微分；

为比热比，是描述气体热力学性质的一个重要参数，和温度相关，通常空气的取1.4；

为理想气体常数；

为初始温度；为初始体积；

为气腔内质量微分；

为气腔内初始压强；

为气腔体积微分。in,

is the differential of the air cavity pressure;

is the specific heat ratio, which is an important parameter describing the thermodynamic properties of the gas, and is related to the temperature, usually 1.4 for air;

is the ideal gas constant;

is the initial temperature; is the initial volume;

is the mass differential in the air cavity;

is the initial pressure in the air cavity;

is the air cavity volume differential.

The rate of change of gas mass in the gas chamber is controlled by an electromagnetic regulating valve:

(2)

(2)

为电磁调节阀增益；

为电磁调节阀电压指令表示的压强；

为气腔压强。in,

is the gain of the solenoid control valve;

is the pressure indicated by the voltage command of the solenoid regulating valve;

is the air cavity pressure.

The dynamic equation of the cylinder is:

(3)

(3)

为模拟飞行器质量；

为气缸活塞杆质量；

为模拟飞行器加速度；

为库伦摩擦力；

为气腔压强；

为气缸活塞横截面积；

为标准大气压；

为气腔外活塞杆横截面积。in,

is the quality of the simulated aircraft;

is the mass of the cylinder piston rod;

to simulate the acceleration of the aircraft;

is the Coulomb friction;

is the air cavity pressure;

is the cross-sectional area of the cylinder piston;

is the standard atmospheric pressure;

is the cross-sectional area of the piston rod outside the air chamber.

The mathematical description of the ventilation duct is:

(4)

(4)

为通气管道另一端气体质量流速；

为通气管道长度；

为时间；

，

是空气动态粘度，D是管道直径；T为温度；P为通气管道压强；c为声速；

为通气管道一端气体质量流速。in,

is the gas mass flow rate at the other end of the ventilation pipe;

is the length of the ventilation pipe;

for time;

,

is the dynamic viscosity of air, D is the diameter of the pipe; T is the temperature; P is the pressure of the ventilation pipe; c is the speed of sound;

is the gas mass flow rate at one end of the ventilation pipe.

According to the knowledge of control theory, the input is the control voltage of the electromagnetic regulating valve, and the output is the state space equation of the air chamber pressure or the vertical displacement of the cylinder piston:

(5)

(5)

为系统状态1；

为系统状态2；

为系统状态3；

为模拟飞行器位移；

为模拟飞行器速度；

为气腔内压强。in,

is system state 1;

is system state 2;

is system state 3;

To simulate the displacement of the aircraft;

to simulate the speed of the aircraft;

is the pressure in the air cavity.

Putting formulas (1), (2), (3) and (4) into formula (5), we can get:

(6)

(6)

为模拟飞行器速度；

为标准大气压；

为气腔内压强的微分；为自然对数；

，

是空气动态粘度，D是管道直径；

为第二控制器的控制量。其中，第二控制器的控制量可以是：与气腔压强和气缸活塞位移有线性关系的量，用于控制气腔内的压强，从而控制气缸活塞位移。in,

to simulate the speed of the aircraft;

is the standard atmospheric pressure;

is the differential of the pressure in the air cavity; is the natural logarithm;

,

is the air dynamic viscosity, D is the pipe diameter;

is the control quantity of the second controller. Wherein, the control quantity of the second controller may be a quantity that has a linear relationship with the pressure of the air chamber and the displacement of the cylinder piston, and is used to control the pressure in the air chamber, thereby controlling the displacement of the cylinder piston.

Further, the electromagnetic regulating valve may include a coarse regulating valve and a fine regulating valve. The second controller is specifically used to: determine the air intake or air output of the cylinder according to the motion state of the simulated aircraft and the pressure measured by the pressure sensor; The gas volume in the cylinder, otherwise adjust the gas volume in the cylinder through the fine adjustment valve. The preset threshold value may be determined according to the adjustment precision of the coarse adjustment valve and the fine adjustment valve, and the value of the preset threshold value is not limited in this application.

For example, when the intake air volume of the cylinder is greater than a preset threshold, the coarse intake solenoid valve can be opened to quickly charge a large amount of air into the cylinder; when the intake air volume of the cylinder is not greater than the preset threshold, the fine intake can be opened Solenoid valve to achieve high-precision control of the amount of inflation. When the air output of the cylinder is greater than the preset threshold, the coarse air outlet solenoid valve can be opened to quickly exhaust to the outside world; when the air output of the cylinder is not greater than the preset threshold, the fine air outlet solenoid valve can be opened to achieve high-precision control exhaust volume. Generally, during the vertical floating process of the simulated aircraft, the air intake or air storage volume is relatively large. At this time, the pressure in the cylinder can be adjusted through the coarse adjustment valve. In the process of fine-tuning the vertical position of the simulated aircraft, Then a fine regulating valve with high precision can be used to control the pressure in the cylinder.

Further, the second controller is specifically configured to: determine the intake air volume or the air output volume of the cylinder by adopting the dual-valve segmented Schmises predictive control algorithm according to the motion state of the simulated aircraft and the pressure measured by the pressure sensor. The double-valve segmented Smith predictive control algorithm is adopted to solve the influence of the delay caused by the adjustment of the solenoid valve and the ventilation pipeline. The use of this strategy will bring the early action of the control output without time delay, which will speed up the control process.

Further, the second controller is also used to obtain the jet mass consumed by the simulated aircraft, and adjust the gas volume in the cylinder according to the jet mass consumed by the simulated aircraft. Combined with the constant pressure control method of the second controller, the simulated aircraft mass that needs to be brought into formula (6) can be determined according to the initial weight of the simulated aircraft and the consumed jet mass, so as to calculate the real-time control amount.

In specific implementation, the jet mass consumed by the simulated aircraft can be obtained directly from the monitoring data provided by the simulated aircraft, or the jet mass consumed by the simulated aircraft can be calculated according to parameters such as the size of the jet port, jet pressure, and jet thrust of the simulated aircraft, or A weighing device is installed at the bottom of the simulated aircraft to collect the real-time weight of the simulated aircraft.

On the basis of any of the above embodiments, a monocular industrial camera is used to measure the plane two-dimensional position of the simulated aircraft, and the first controller controls the X-axis servo motor and the Y-axis servo motor based on the two-dimensional position data of the simulated aircraft, so that the The two-dimensional mobile platform follows and tracks the horizontal two-dimensional movement of the simulated aircraft. At the same time, the first controller is also used to obtain the jet mass consumed by the simulated aircraft, and controls the Z-axis servo motor to adjust the tension of the suspension wire according to the jet mass consumed by the simulated aircraft and the tension of the suspension wire.

The following describes how the first controller controls the two-dimensional moving platform and the Z-axis servo motor in the dynamic simulation process.

First of all, the mathematical description of the motion of the two-dimensional mobile platform in the horizontal plane is:

(7)

(7)

为二维移动平台沿X轴向等效平移质量；

为悬挂物质量；

为二维移动平台沿X轴向的加速度；

为二维移动平台沿X轴向的阻尼系数；

为二维移动平台沿X轴向的速度；

的角加速度；

为二维移动平台沿X轴向受到的电机驱动力；

为二维移动平台沿Y轴向等效平移质量；

为二维移动平台沿Y轴向的加速度；

为二维移动平台沿Y轴向的阻尼系数；

为二维移动平台沿Y轴向的速度；

为悬线长度；

的角加速度；

为二维移动平台沿Y轴向受到的电机驱动力；I为Z轴伺服电机绕轴等效转动惯量；

为悬线收线加速度(悬线长度的二阶微分)；

为沿

向的阻尼系数；

为悬线收线速度(悬线长度的微分)；g为重力加速度；

为悬线张力；

为悬线摆动中的等效阻尼系数；

的角速度；、

为悬线空间摆动位置的欧拉转角；

为的角速度；

为模拟飞行器受到沿X轴的其他外力；

为模拟飞行器受到沿Y轴的其他外力。in,

is the equivalent translation mass of the two-dimensional mobile platform along the X axis;

is the mass of suspended objects;

is the acceleration of the two-dimensional mobile platform along the X axis;

is the damping coefficient of the two-dimensional moving platform along the X axis;

is the speed of the two-dimensional moving platform along the X axis;

angular acceleration;

is the motor driving force received by the two-dimensional mobile platform along the X axis;

is the equivalent translation mass of the two-dimensional mobile platform along the Y axis;

is the acceleration of the two-dimensional mobile platform along the Y axis;

is the damping coefficient of the two-dimensional moving platform along the Y axis;

is the speed of the two-dimensional moving platform along the Y axis;

is the length of the suspension line;

angular acceleration;

is the motor driving force received by the two-dimensional mobile platform along the Y axis; I is the equivalent moment of inertia of the Z axis servo motor around the axis;

is the acceleration of the suspension wire (the second derivative of the length of the suspension wire);

for the edge

damping coefficient in the direction;

is the take-up speed of the suspension wire (differential of the length of the suspension wire); g is the acceleration of gravity;

is the suspension tension;

is the equivalent damping coefficient in the pendulum swing;

angular velocity;

is the Euler angle of the pendulum space swing position;

is the angular velocity;

To simulate other external forces along the X-axis;

To simulate other external forces along the Y-axis.

The horizontal two-dimensional motion is decoupled in the vertical and horizontal directions, and the two directions of the X-axis and the Y-axis are symmetrical, so the mathematical description of the two-dimensional motion can be obtained as:

(8)

(8)

为悬线长度；F为二维移动平台沿X轴向或Y轴向受到的电机驱动力；

的角速度；

为悬线空间摆动位置的欧拉转角；

为模拟飞行器受到沿X轴向或Y轴向的其他外力。Among them, M is the equivalent translation mass of the two-dimensional moving platform along the X-axis or Y-axis; C is the damping coefficient of the two-dimensional moving platform along the X-axis or the Y-axis;

is the length of the suspension line; F is the motor driving force received by the two-dimensional moving platform along the X-axis or the Y-axis;

angular velocity;

is the Euler angle of the pendulum space swing position;

To simulate other external forces along the X-axis or Y-axis.

The mathematical description of the vertical suspension force is:

(9)

(9)

Among them, R is the Z-axis motor reel radius.

Based on equations (7)-(9) and related parameters, including the equivalent translational mass acceleration, damping coefficient, velocity, suspension mass, suspension wire length, and Z-axis servo motor around the axis of the two-dimensional mobile platform along the X-axis and Y-axis Equivalent moment of inertia, etc., calculate the motor driving force along the X-axis and Y-axis of the two-dimensional mobile platform, other external forces along the X-axis and Y-axis of the simulated aircraft, and the tension of the suspension wire, and then the two-dimensional mobile platform and axis Servo motor for control.

The combined three-dimensional microgravity simulation system suitable for satellite ground simulation proposed by the embodiment of the present application can adjust the cylinder pressure or the suspension wire tension according to the jet mass consumed by the simulated aircraft, so as to deal with the problem of the quality change of the simulated aircraft during the simulation process, It provides a real-time 3D microgravity simulation environment for variable-mass simulated aircraft. Compared with the traditional constant force ground microgravity simulation, it has the advantages of wide application range and strong practicability.

On the basis of any of the above-mentioned embodiments, the vertical air bearing microgravity simulation unit further includes a grating ruler, and the grating ruler is used to measure the height of the vertical cylinder in the vertical direction. Based on the grating ruler, the real-time height of the vertical cylinder in the vertical direction can be accurately known, so as to better control the vertical cylinder and the suspension wire, and solve the problem that the initial state of the vertical microgravity simulation is difficult to give.

In the actual simulation process, the pipeline of the vertical cylinder exhaust will interfere with the system. The length of the pipeline increases as the vertical cylinder rises, and pipelines with different lengths will bring different disturbances. In order to deal with the above interference, the air flotation force caused by the vertical cylinder's outward exhaust can be measured in advance when the vertical cylinder moves to different heights, and then the corresponding relationship table between the vertical cylinder height and the air flotation force can be obtained. When the vertical cylinder is exhausted to the outside, the second controller may send a relevant signal to the first controller to notify the first controller that the vertical cylinder is exhausting to the outside. The first controller is also used for: when it is detected that the vertical cylinder is exhausted to the outside, the height of the vertical cylinder in the vertical direction measured based on the grating ruler, and the corresponding relationship between the pre-measured vertical cylinder height and the air flotation force Table, determine the current air flotation power of the vertical cylinder; according to the current air flotation power, adjust the tension of the suspension wire through the Z-axis servo motor to balance the current air flotation power of the vertical cylinder. Through the above method, the disturbance caused by the vertical cylinder's outward exhaust can be compensated, and the simulation accuracy of the system can be improved.

When the simulated aircraft jets out, it will also bring a certain disturbance to the system. For this reason, the first controller is also used to: determine the disturbance force received by the simulated aircraft according to the size of the jet port, the jet pressure and the jet thrust of the simulated aircraft. ;According to the disturbance force received by the simulated aircraft, adjust the pulling force of the suspension wire through the Z-axis servo motor to balance the disturbance force of the simulated aircraft. The above method can compensate for the disturbance caused by the simulated aircraft's outward exhaust, and improve the simulation accuracy of the system.

During specific implementation, the first controller can calculate the disturbance force received by the simulated aircraft in the vertical direction, and adjust the pulling force of the suspension wire through the Z-axis servo motor to balance the disturbance force received by the simulated aircraft in the vertical direction. Usually, the air outlet direction of the air outlet of the simulated aircraft is in the vertical direction, and the disturbance force received by the simulated aircraft acts in the vertical direction; if the air outlet of the simulated aircraft has a certain angle with the vertical direction, the simulated aircraft can be calculated according to the angle Perturbation force in the vertical direction.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, All should be covered within the scope of protection of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. a combined three-dimensional microgravity simulation system applicable to satellite ground simulation, is characterized in that, comprises: vertical air-floating microgravity simulation unit, suspension microgravity simulation unit and smooth platform; The vertical air flotation microgravity simulation unit includes a vertical air cylinder, the vertical air cylinder is suspended above the smooth platform through a horizontal air foot and moves in the horizontal direction, and the gas pressure balance in the vertical air cylinder is adjusted by adjusting the air pressure in the vertical air cylinder. A part of the gravity of the simulated aircraft fixed on the top of the vertical cylinder; The suspended microgravity simulation unit includes a two-dimensional mobile platform, a suspension wire, a Z-axis servo motor, a tension sensor, a positioning device and a first controller. The two-dimensional mobile platform is erected above the smooth platform. The mobile platform can move in the horizontal direction, the Z-axis servo motor arranged on the two-dimensional mobile platform is connected with the simulated aircraft through the suspension wire, and the positioning device is used to measure the position of the simulated aircraft, so the The tension sensor is used to measure the tension of the suspension wire; the first controller is used to control the two-dimensional moving platform to follow the simulated aircraft to move according to the position of the simulated aircraft measured by the positioning device, so as to Keep the suspension wire upright, and control the Z-axis servo motor to retract or release the suspension wire according to the pulling force of the suspension wire measured by the tension sensor, so as to balance a part of the gravity of the simulated aircraft . 2 . The system according to claim 1 , wherein the first controller is further configured to obtain the jet mass consumed by the simulated aircraft, according to the jet mass consumed by the simulated aircraft and the pulling force of the suspension wire. 3 . , and control the Z-axis servo motor to adjust the tension of the suspension wire. 3. The system of claim 1, wherein the first controller is further configured to: Obtain the size of the jet port, jet pressure and jet thrust of the simulated aircraft, and determine the disturbance force received by the simulated aircraft; According to the disturbance force received by the simulated aircraft, the pulling force of the suspension wire is adjusted by the Z-axis servo motor to balance the disturbance force of the aircraft. 4 . The system according to claim 1 , wherein the vertical air-floating microgravity simulation unit further comprises a grating ruler, which is used to measure the height of the vertical air cylinder in the vertical direction. 5 . 5. The system of claim 4, wherein the first controller is further configured to: When it is detected that the vertical cylinder is exhausted to the outside, based on the height of the vertical cylinder in the vertical direction measured by the grating ruler, and the correspondence table between the height of the vertical cylinder and the air flotation force measured in advance, determining the air flotation power currently received by the vertical cylinder; According to the current air buoyancy disturbance force, the pulling force of the suspension wire is adjusted by the Z-axis servo motor to balance the air buoyancy disturbance force currently received by the vertical cylinder. 6. The system according to any one of claims 1 to 5, wherein the vertical cylinder comprises an air cylinder, an electromagnetic regulating valve, a high-pressure gas cylinder, a ventilation pipe, a pressure sensor and a second controller; The air outlet of the high-pressure gas cylinder is communicated with the air inlet of the cylinder through the ventilation pipe, and the air outlet and the air inlet of the air cylinder are respectively equipped with electromagnetic regulating valves; the pressure sensor is used to measure the pressure in the cylinder; The second controller is used for controlling the opening and closing of the electromagnetic regulating valve according to the motion state of the simulated aircraft and the pressure measured by the pressure sensor, so as to increase or decrease the gas in the cylinder. 7. The system of claim 6, wherein the solenoid regulating valve comprises a coarse regulating valve and a fine regulating valve; The second controller is specifically used to: determine the air intake or air output of the cylinder according to the motion state of the simulated aircraft and the pressure measured by the pressure sensor; if the air intake or the air output is greater than a preset amount If the threshold value is set, the gas volume in the cylinder is adjusted through the coarse adjustment valve, otherwise the gas volume in the cylinder is adjusted through the fine adjustment valve. 8 . The system according to claim 7 , wherein the second controller is specifically configured to: according to the motion state of the simulated aircraft and the pressure measured by the pressure sensor, use a two-valve segmented Schmises A predictive control algorithm determines the amount of intake or exhaust of the cylinder. 9 . The system according to claim 6 , wherein the second controller is further configured to: obtain the jet mass consumed by the simulated aircraft, and adjust the air jet mass in the cylinder according to the jet mass consumed by the simulated aircraft. 10 . amount of gas. 10. The system according to any one of claims 1 to 5, wherein the suspended microgravity simulation unit further comprises an X-axis linear slide rail, a Y-axis linear slide rail, an X-axis servo motor and a Y-axis servo motor ; A support frame is arranged on the smooth platform, X-axis linear slide rails arranged in parallel are installed on both sides of the support frame, and Y-axis linear slide rails are installed in parallel between the X-axis linear slide rails. The Y-axis linear slide rail is driven to move along the X-axis linear slide rail, the two-dimensional moving platform is installed between the Y-axis linear slide rails, and the two-dimensional moving platform is driven by the Y-axis servo motor to move along the Y-axis linear slide rail.

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